Injury to the articular cartilage occurs commonly in the general population and undergoes minimal spontaneous healing. Traditional methods of cartilage repair provide no long-term cure and are significant causes of morbidity. For this reason, stem cell therapies have recently been investigated for their ability to regenerate cartilage, and the results have been promising. Since the discovery that adipose tissue is a major source of mesenchymal stem cells in 2001, scientists have been studying the use of adipose-derived stem cells (ASCs) for the treatment of various disorders including lesions of the articular cartilage. ASCs hold several advantages over autologous chondrocytes for cartilage repair, including but not limited to their anti-inflammatory effects, their multi-lineage differentiation potential, and their ability to form new cartilage in a defect. Whereas several investigations have been made in in vitro and animal models, there have been surprisingly little clinical studies on the intra-articular use of adipose-derived stem cells, despite their first isolation about a decade and a half ago. The few studies that have been conducted are encouraging. With approval for various stem cell therapies on the horizon, this review seeks to update the clinician and the researcher on the current state-of-the-art use of adipose-derived stem cells for the treatment of cartilage disorders and the regenerative engineering of cartilaginous tissue.

Inductive biomaterials are sought as alternatives to traditional materials used to treat bone defects. Traditional materials include autologous bone grafts that must be obtained surgically, and allografts that carry the risk of disease transmission and infection. Whereas the use of growth factors to stimulate bone growth has seen considerable advances, their efficacy is usually limited to supra-physiological doses with considerable side effects. On the other hand, certain biomaterials have an intrinsic ability to stimulate bone regeneration in lieu of growth factor use, and their use in repairing bone defects as well as improving the osteointegration of implants has been promising. These materials known as osteoinductive biomaterials include ceramics, metals, polymers, and composites of these materials. In this review, we examine the relevant properties of these different materials in their ability to induce bone formation.